Restrained eating predicts effortful self-control as indicated by heart rate variability during food exposure

Predicting Fatigue-Associated Aberrant Driving Behaviors Using a Dynamic Weighted Moving Average Model With a Long Short-Term Memory Network Based on Heart Rate Variability

OBJECTIVE

This study proposed a moving average (MA) approach to dynamically process heart rate variability (HRV) and developed aberrant driving behavior (ADB) prediction models by using long short-term memory (LSTM) networks.

BACKGROUND

Fatigue-associated ADBs have traffic safety implications. Numerous models to predict such acts based on physiological responses have been developed but are still in embryonic stages.

METHOD

This study recorded the data of 20 commercial bus drivers during their routine tasks on four consecutive days and subsequently asked them to complete questionnaires, including subjective sleep quality, driver behavior questionnaire and the Karolinska Sleepiness Scale. Driving behaviors and corresponding HRV were determined using a navigational mobile application and a wristwatch. The dynamic-weighted MA (DWMA) and exponential-weighted MA were used to process HRV in 5-min intervals. The data were independently separated for training and testing. Models were trained with 10-fold cross-validation strategy, their accuracies were evaluated, and Shapley additive explanation (SHAP) values were used to determine feature importance.

RESULTS

Significant increases in the standard deviation of NN intervals (SDNN), root mean square of successive heartbeat interval differences (RMSSD), and normalized spectrum of high frequency (nHF) were observed in the pre-event stage. The DWMA-based model exhibited the highest accuracy for both driver types (urban: 84.41%; highway: 80.56%). The SDNN, RMSSD, and nHF demonstrated relatively high SHAP values.

CONCLUSION

HRV metrics can serve as indicators of mental fatigue. DWMA-based LSTM could predict the occurrence of the level of fatigue associated with ADBs.

APPLICATION

The established models can be used in realistic driving scenarios.

Machine learning model for aberrant driving behaviour prediction using heart rate variability: a pilot study involving highway bus drivers

Objectives. Current approaches via physiological features detecting aberrant driving behaviour (ADB), including speeding, abrupt steering, hard braking and aggressive acceleration, are developing. This study proposes using machine learning approaches incorporating heart rate variability (HRV) parameters to predict ADB occurrence. Methods. Naturalistic driving data of 10 highway bus drivers in Taiwan from their daily routes were collected for 4 consecutive days. Their driving behaviours and physiological data during a driving task were determined using a navigation mobile application and heart rate watch. Participants' self-reported data on sleep, driving-related experience, open-source data on weather and the traffic congestion level were obtained. Five machine learning models - logistic regression, random forest, naive Bayes, support vector machine and gated recurrent unit (GRU) - were employed to predict ADBs. Results. Most drivers with ADB had low sleep efficiency (≤80%), with significantly higher scores in driver behaviour questionnaire subcategories of lapses and errors and in the Karolinska sleepiness scale than those without ADBs. Moreover, HRV parameters were significantly different between baseline and pre-ADB event measurements. GRU had the highest accuracy (81.16-84.22%). Conclusions. Sleep deficit may be related to the increased fatigue level and ADB occurrence predicted from HRV-based models among bus drivers.

Disconnect between sympathetically-induced hunger suppression and consumption among highly restrained eaters following stress

Despite emphasis on findings suggesting restrained eaters increase food consumption under stress, unrestrained eaters' reduction in intake is more robust. Early proposals asserted unrestrained eaters significantly reduced intake after certain threats due to the hunger-inhibiting effects of autonomic influences, presuming unrestrained eaters are more responsive to these effects and restrained eaters rely less on physiological cues for eating. However, scant empirical evidence has substantiated these claims. This study examined whether a sequence exists whereby stress elicits autonomic activation, autonomic activation impacts hunger, and hunger then impacts eating, with dietary restraint altering the hunger-intake link. It was hypothesized that sympathetic nervous system activation would be greatest when ongoing safety from stress was uncertain, sympathetic activation would be linked to reduced hunger, and lower hunger would be associated with attenuated intake. Restraint, conceptualized via Hagan et al.'s (2017) latent restraint factors, was hypothesized to reduce the association between hunger and intake. Female participants (n = 147) were randomized to a stress + certain safety, stress + uncertain safety, or control condition. Sympathetic nervous system activity was recorded prior to a bogus taste test, which quantified ad libitum consumption of highly-palatable snack foods post-stress. Only the stress + uncertain safety condition exhibited greater sympathetic nervous system activity than the control condition. A significant index of moderated serial mediation emerged for Preoccupation with Dieting and Weight-Focused Restraint in the stress + uncertain safety condition. Though sympathetic activation decreased hunger similarly regardless of dietary restraint, only less restrained individuals significantly decreased intake. More restrained individuals ate more despite experiencing lower hunger. The disconnect between hunger and intake in more restrained eaters suggests that focus on enhancing attunement to hunger may yield greater benefit than enhancing restraint. 281 words.

Improvement in parasympathetic regulation is associated with engagement in classroom activity in primary school children experiencing poor classroom climate

BACKGROUND

Self-regulation promotes engagement within the classroom. At a physiological level, a good indicator of the ability of the system to self-regulate is cardiac vagal tone (CVT).

AIMS

The present study aims to assess children's change over time (1 year) in their parasympathetic regulation (by way of CVT) in response to a social and cognitive stressor. Moreover, it addresses whether, if present, this change over time in regulation influences students' engagement in classroom activities while also accounting for classroom climate.

SAMPLE

Forty-nine second graders were assessed at two time points: November 2018 (T1) and 1 year later in 2019 (T2).

METHODS

Children's CVT was registered at rest and while performing a stressful task during which they were asked to cognitively perform while being socially evaluated. Children were also interviewed on how much they feel engaged in classroom activities and their perceptions of classroom climate.

RESULTS

A repeated measures analysis of variance including 2 Time Points ×2 Phases of CVT Registration (baseline and during the stressful task) revealed a significant decrease in cardiac vagal activity from baseline to the task at T1, indicating that initially most children were not able to self-regulate and gave way to a stress response when facing the stressful task. The pattern changed at T2 when an active regulation took place signalled by an increase in CVT from baseline to the stressful task. Data analysis also revealed that among children who perceived a poorer classroom climate, the display of greater parasympathetic regulation over time was linked with higher active engagement in classroom activities.

CONCLUSIONS

Growth in physiological regulation in response to a challenging task is associated with better engagement in classroom activities. Interventions and educational practice promoting the development of self-regulation strategies are recommended.

Autonomic Nervous System Activity During Positive Emotions: A Meta-Analytic Review

Autonomic nervous system (ANS) activity is a fundamental component of emotional responding. It is not clear, however, whether positive emotional states are associated with differential ANS reactivity. To address this issue, we conducted a meta-analytic review of 120 articles (686 effect sizes, total N = 6,546), measuring ANS activity during 11 elicited positive emotions, namely amusement, attachment love, awe, contentment, craving, excitement, gratitude, joy, nurturant love, pride, and sexual desire. We identified a widely dispersed collection of studies. Univariate results indicated that positive emotions produce no or weak and highly variable increases in ANS reactivity. However, the limitations of work to date – which we discuss – mean that our conclusions should be treated as empirically grounded hypotheses that future research should validate.

The ironic effects of dietary restraint in situations that undermine self-regulation

Dietary restraint, defined as the cognitive effort to restrict eating, can paradoxically make individuals more susceptible to unhealthy eating when their ability to self-regulate is threatened. Past experiments have found that, in situations that elicit low self-control and/or unhealthy cravings, participants with higher dietary restraint eat more than those with lower restraint. However, these relationships have never been examined in a free-living environment. The current daily diary study examined if dietary restraint would exacerbate the associations between poor self-control and unhealthy cravings with overconsumption, namely, eating more than usual and binge eating. College women (N = 121, M age = 19) reported their restrained eating behavior and completed seven daily surveys. Multilevel analyses showed a significant interaction between dietary restraint and daily self-control on eating more than usual (b = -0.13, p = .001) and binge eating (b = -0.22, p < .001). Lower daily self-control was associated with eating more than usual and with more binge eating that day, but only among women with higher dietary restraint. Dietary restraint also moderated the effect of cravings on eating more than usual (b = 0.10, p = .007); this relationship was stronger for women with higher restraint. Stronger cravings were associated with more binge eating regardless of restraint. Results suggest that situations that undermine self-control are more strongly associated with overeating among those with higher dietary restraint. Findings can inform strategies to reduce overconsumption among restrained eaters.

Mindfulness-oriented recovery enhancement reduces opioid dose in primary care by strengthening autonomic regulation during meditation

The current opioid crisis was fueled by escalation of opioid dosing among patients with chronic pain. Yet, there are few evidence-based psychological interventions for opioid dose reduction among chronic pain patients treated with long-term opioid analgesics. Mindfulness-Oriented Recovery Enhancement (MORE), which was designed to target mechanisms underpinning chronic pain and opioid misuse, has shown promising results in 2 randomized clinical trials (RCTs) and could facilitate opioid sparing and tapering by bolstering self-regulation. Here we tested this hypothesis with secondary analyses of data from a Stage 2 RCT. Chronic pain patients (N = 95) on long-term opioid therapy were randomized to 8 weeks of MORE or a support group (SG) control delivered in primary care. Opioid dose was assessed with the Timeline Followback through 3-month follow-up. Heart rate variability (HRV) during mindfulness meditation was quantified as an indicator of self-regulatory capacity. Participants in MORE evidenced a greater decrease in opioid dosing (a 32% decrease) by follow-up than did the SG, F(2, 129.77) = 5.35, p = .006, d = 1.07. MORE was associated with a significantly greater increase in HRV during meditation than was the SG. Meditation-induced change in HRV partially mediated the effect of MORE on opioid dose reduction (p = .034). MORE may boost self-regulatory strength via mindfulness and thereby facilitate self-control over opioid use, leading to opioid dose reduction in people with chronic pain. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Resting state heart rate variability in clinical and subthreshold disordered eating: A meta-analysis

OBJECTIVE

Research has demonstrated mixed results regarding the direction of the association between vagal activation and disordered eating. The current meta-analysis examined studies testing the link between resting-state heart rate variability indices of vagal activation (vmHRV), and both clinical and subthreshold disordered eating.

METHOD

A systematic search of the literature resulted in the inclusion of studies that were correlational (associations between HRV and disordered eating symptoms) and that examined group differences (e.g., control group vs. disordered eating group), for a total of 36 samples.

RESULTS

Findings indicated a small but reliable association of vmHRV with disordered eating, r = 0.12, indicating greater vagal activation in individuals with disordered eating compared to those with little or no disordered eating behavior. Moderation analyses identified predictors of the vmHRV/disordered eating association. Bulimia nervosa was found to have a large, positive effect size with vmHRV, r = 0.60, which was significantly greater than all other types of disordered eating, Q _T = 10.74, p = .047. Compared to subthreshold disordered eating, clinical eating disorders demonstrated significant, persistent increased vagal activation with a medium, reliable effect size, r = 25, Q_T = 3.94, p = .045.

CONCLUSION

These insights contribute to an improved understanding of the pathophysiology in disordered eating.

Go/no-go for food: Attention bias and intention to eat unhealthy food

OBJECTIVE

The current research evaluated whether Go/No-go training for highly palatable (HP) food affected attention bias for HP food (an automatic/implicit outcome) and intention to eat unhealthy food (a controlled/explicit outcome).

METHOD

A sample of Australian adults representative for age, gender and Body Mass Index (BMI) (N = 561, M_age = 46.31 years, SD = 16.75, 52.3% women, M_BMI = 27.11, SD = 6.34) completed self-report measures of dietary psychological constructs and food image modified Stroop tasks as measures of pre- and post-test attention bias for HP food. After random assignment of participants to two conditions, a Go/No-go intervention was used to train HP food targeted inhibitory control in the experimental group, or general inhibitory control in the control group. All research tasks were delivered online.

RESULTS

The experimental, HP food inhibitory control training group reported intention to eat less unhealthy food than the control group, F (1, 637) = 4.81, R² = 0.09, p = .029. Counter to expectations, the experimental group exhibited a heightened attention bias to HP food images after the training, F (1, 637) = 9.48, R² = 0.39, p = .002.

CONCLUSION

Go/No-go training for food may improve both top-down and bottom-up inhibitory control, using both automatic and controlled processes. Further, it may not be effective in lowering attention bias for HP food, but may be effective in lowering unhealthy food intake despite raising attention bias for HP food. Further research that tests these effects using varied reaction time tasks is needed to confirm these results and to explore possible alternative explanations.

Heart-rate variability: a biomarker to study the influence of nutrition on physiological and psychological health?

As the influence of diet on health may take place over a period of decades, there is a need for biomarkers that help to identify those aspects of nutrition that have either a positive or a negative influence. The evidence is considered that heart-rate variability (HRV) (the time differences between one beat and the next) can be used to indicate the potential health benefits of food items. Reduced HRV is associated with the development of numerous conditions for example, diabetes, cardiovascular disease, inflammation, obesity and psychiatric disorders. Although more systematic research is required, various aspects of diet have been shown to benefit HRV acutely and in the longer term. Examples include a Mediterranean diet, omega-3 fatty acids, B-vitamins, probiotics, polyphenols and weight loss. Aspects of diet that are viewed as undesirable, for example high intakes of saturated or trans-fat and high glycaemic carbohydrates, have been found to reduce HRV. It is argued that the consistent relationship between HRV, health and morbidity supports the view that HRV has the potential to become a widely used biomarker when considering the influence of diet on mental and physical health.

The Benefits of a Mindfulness Exercise in a Performance Situation

Background Mindfulness is a state of nonjudgmental attentiveness to moment-to-moment experiences. Interest in implementing mindfulness-based interventions is growing. Objective We investigated the benefit of a short mindfulness exercise for mindfulness novices in a performance situation. Method Participants ( N = 97) engaged in a mindfulness or relaxation exercise and subsequently worked on an achievement test. Results Participants in the mindfulness condition had fewer distracting evaluative thoughts during and experienced less negative affect after the achievement test. Participants also exerted less self-control (vagal withdrawal measured via heart rate variability) during the mindfulness exercise than on the relaxation exercise. In a subsample ( n = 84), selected on the basis of serious involvement in the exercise, mindfulness eliminated the negative association between distracting evaluative thoughts and performance. Furthermore, beneficial effects of mindfulness on distractive thoughts were found for participants low but not high in trait mindfulness. The mindfulness exercise did not influence performance. Conclusion In performance contexts, even brief mindfulness exercises may have beneficial effects for mindfulness novices and people low in trait mindfulness.

Is intuitive eating related to resting state vagal activity?

Efferent and afferent fibers of the vagus nerve are involved in regulating hunger and satiety. Vagally-mediated heart rate variability (vmHRV) reflects vagal activity. Previously no study addressed a potential association between resting state vagal activity and intuitive eating. Self-reports on intuitive eating and measures of resting state vmHRV were obtained in 39 students (16 female, mean age: 19.64±1.44years). Hierarchical multiple regression models showed that, after controlling for gender, age, and body mass index, resting vagal activity was inversely related to the Unconditional Permission to Eat subscale of the Intuitive Eating scale. Individuals with higher resting vagal activity tend to be less willing to eat desired foods and are more likely to label certain foods as forbidden. Future studies should include measures of self-regulation and eating disorder symptomatology to identify potential mediators or moderators when attempting to replicate these preliminary findings in larger samples.

Weight bias, health consciousness and behavioral actions (activities)

OBJECTIVE

This study examines the influence of weight bias and health consciousness on eating and dietary behavior; it also investigates the role of normative influences.

DESIGN AND METHODS

A sample of adults living in South-East England (N=498) completed anonymous questionnaires about their diet, attitudes and beliefs towards obese people, health consciousness and normative influences. The survey included validated measures of anti-fat attitudes, and beliefs about obese people.

RESULTS

The findings demonstrate anti-fat attitudes are positively related to self-perceived dietary behavior. Surprisingly, self-perceived dietary behavior is negatively related to health consciousness and activities designed to enable healthy eating, for example meal planning. Significant differences exist between people with, or without, obese family members.

CONCLUSIONS

Attempts to improve eating behavior by raising health consciousness and offering related support activities may fail; promoting health eating may also contribute to weight bias in society. However, interventions which focus on the negative impact of obesity itself may have a positive effect.